Local adipose tissue renin-angiotensin system

Expression levels of ACE and ACE2 in the placenta and white adipose tissue of lean and obese pregnant women

BACKGROUND

This study evaluated the expression of ACE and ACE2 in the placenta and white adipose tissue in lean and obese women, and correlated their levels with anthropometric, clinical, and laboratory parameters, and tissue count of inflammatory cells.

METHODS

A cross-sectional analytical study was performed with 49 pregnant women and their respective newborns. Samples of placenta and adipose tissue were used for measuring mRNA expression for ACE and ACE2 through qRT-PCR. Inflammatory cell counting was performed through conventional microscopy.

RESULTS

An increase in ACE expression and a decrease in ACE2 were observed in the placenta and adipose tissue of women with obesity. ACE2 levels showed a negative correlation with pre-pregnancy BMI and total cholesterol.

CONCLUSION

Maternal obesity can modulate the expression of RAS components in the placenta and white adipose tissue, with ACE2 correlated with pre-pregnancy BMI and total cholesterol.

The Prevalence of Metabolic Syndrome and Its Association With Waist Circumference in Middle-Aged Individuals From Urban Mumbai

Background Metabolic syndrome (MetS) represents a critical public health challenge globally, characterized by a cluster of metabolic abnormalities that heighten the risk of cardiovascular diseases and type 2 diabetes. In India, the prevalence of MetS, particularly in urban areas, is rising rapidly. This study investigates the prevalence of MetS and its association with waist circumference in middle-aged individuals from urban Mumbai. Methods A cross-sectional study was conducted among 1,851 participants (814 men and 1,037 women, with a mean age of 56.8 years) in a public health camp in urban Mumbai. Data were collected on anthropometric measures, blood pressure, and blood markers, including fasting glucose and lipid profiles. MetS was diagnosed based on the National Cholesterol Education Program Adult Treatment Panel III (NCEP ATP III) criteria. This included the presence of three or more of the following five criteria: waist circumference of ≥102 cm for men and ≥88 cm for women, fasting triglycerides of ≥150 mg/dL, fasting high-density lipoprotein (HDL) cholesterol of <40 mg/dL for men and <50 mg/dL for women, blood pressure of ≥130/85 mm Hg, and fasting glucose of ≥100 mg/dL. Data were analyzed using SPSS Statistics version 23 (IBM SPSS Statistics, Armonk, NY). Statistical analyses were performed using the chi-square test, with statistical significance set at p<0.05. Results The overall prevalence of metabolic syndrome (MetS) in the cohort was 32.6% (605 out of 1,851 participants), with women exhibiting a significantly higher prevalence at 38% (394 out of 1,037 women) compared to men at 26% (211 out of 814 men) (p<0.001). High waist circumference (≥102 cm for men and ≥88 cm for women) was strongly correlated with MetS, as 73.8% of individuals (314 out of 425 participants) in the high waist circumference group met the criteria for MetS, compared to 20.4% of individuals (291 out of 1,426 participants) in the non-high waist circumference group (<102 cm for men and <88 cm for women) (p<0.001). Furthermore, elevated blood pressure, elevated fasting glucose, and elevated fasting triglycerides were significantly more common in the high waist circumference group, than in the non-high waist circumference group (p<0.001). Conclusion The study highlights the significant association between central obesity and MetS in an urban Indian population, with notably higher prevalence in women. Waist circumference is a critical determinant of MetS and should routinely be measured, with significant application especially in resource-limited settings for early detection and intervention.

CD28-expressing δ T cells are increased in perivascular adipose tissue of hypertensive mice and in subcutaneous adipose tissue of obese humans

OBJECTIVES

γδ T-lymphocytes play a role in angiotensin II (AngII)-induced hypertension, vascular injury and T-cell infiltration in perivascular adipose tissue (PVAT) in mice. Mesenteric arteries of hypertensive mice and subcutaneous arteries from obese humans present similar remodeling. We hypothesized that γδ T-cell subtypes in mesenteric vessels with PVAT (MV/PVAT) from hypertensive mice and subcutaneous adipose tissue (SAT) from obese humans, who are prone to develop hypertension, would be similar.

METHODS

Mice were infused with AngII for 14 days. MV/PVAT T-cells were used for single-cell RNA-sequencing (scRNA-seq). scRNA-seq data (GSE155960) of SAT CD45 + cells from three lean and three obese women were downloaded from the Gene Expression Omnibus database.

RESULTS

δ T-cell subclustering identified six δ T-cell subtypes. AngII increased T-cell receptor δ variable 4 ( Trdv4 ) + γδ T-effector memory cells and Cd28high δ T EM -cells, changes confirmed by flow cytometry. δ T-cell subclustering identified nine δ T-cell subtypes in human SAT. CD28 expressing δ T-cell subclustering demonstrated similar δ T-cell subpopulations in murine MV/PVAT and human SAT. Cd28+ γδ NKT EM and Cd28high δ T EM -cells increased in MV/PVAT from hypertensive mice and CD28high δ T EM -cells in SAT from obese women compared to the lean women.

CONCLUSION

Similar CD28 + δ T-cells were identified in murine MV/PVAT and human SAT. CD28 high δ T EM -cells increased in MV/PVAT in hypertensive mice and in SAT from humans with obesity, a prehypertensive condition. CD28 + δ T-lymphocytes could have a pathogenic role in human hypertension associated with obesity, and could be a potential target for therapy.

Dysregulation of HO-1-SIRT1 Axis is Associated with AngII-Induced Adipocyte Dysfunction

Angiotensin II (AngII), a component of the Renin-Angiotensin-Aldosterone System (RAAS), has been implicated in the dysregulation of adipose tissue function. Inhibition of AngII has been shown to improve adipose tissue function in mice with metabolic syndrome. It is well established that the Heme Oxygenase-1 (HO-1), an antioxidant improves oxidative stress and phenotypic change in adipocytes. Molecular effects of high oxidative stress include suppression of Sirtuin-1 (SIRT1), which is amenable to redox manipulations. However, the underlying mechanisms by which the Renin-Angiotensin-Aldosterone System (RAAS) exerts its metabolic effects are not fully understood. In this study, we propose that AngII-induced oxidative stress may suppress adipocyte SIRT1 through down-regulation of HO-1. Consequently, this suppression of SIRT1 may result in the up-regulation of the Mineralocorticoid Receptor (MR). We further hypothesize that the induction of HO-1 would rescue SIRT1, thereby improving oxidative stress and adipocyte phenotype. To establish this hypothesis, we conducted experiments using mouse preadipocytes treated with AngII, in the presence or absence of Cobalt Protoporphyrin (CoPP), an inducer of HO-1, and Tin Mesoporphyrin (SnMP), an inhibitor of HO-1. Our data demonstrate that treatment of mouse preadipocytes with AngII leads to increased lipid accumulation, elevated levels of superoxide and inflammatory cytokines (Interleukin-6 and Tumor necrosis factor alpha), and reduced levels of adiponectin. However, these effects were attenuated by the induction of HO-1, and this attenuation was reversed by SnMP, indicating that the beneficial effects on adipocyte phenotype are modulated by HO-1. Furthermore, our findings reveal that AngII-treated preadipocytes exhibit upregulated MR levels and suppressed SIRT1 expression, which are rescued by HO-1 induction. Following treatment with CoPP and SIRT1 siRNA in mouse preadipocytes resulted in increased lipid accumulation and elevated levels of fatty acid synthase, indicating that the beneficial effects of HO-1 are modulated through SIRT1. Our study provides evidence that HO-1 restores cellular redox balance, rescues SIRT1, and attenuates the detrimental effects of AngII on adipocytes and systemic metabolic profile.

Sodium-Glucose Cotransporter Protein 2 Inhibitors: Novel Application for the Treatment of Obesity-Associated Hypertension

Obesity is becoming increasingly prevalent in China and worldwide and is closely related to the development of hypertension. The pathophysiology of obesity-associated hypertension is complex, including an overactive sympathetic nervous system (SNS), activation of the renin-angiotensin-aldosterone system (RAAS), insulin resistance, hyperleptinemia, renal dysfunction, inflammatory responses, and endothelial function, which complicates treatment. Sodium-glucose cotransporter protein 2 (SGLT-2) inhibitors, novel hypoglycemic agents, have been shown to reduce body weight and blood pressure and may serve as potential novel agents for the treatment of obesity-associated hypertension. This review discusses the beneficial mechanisms of SGLT-2 inhibitors for the treatment of obesity-associated hypertension. SGLT-2 inhibitors can inhibit SNS activity, reduce RAAS activation, ameliorate insulin resistance, reduce leptin secretion, improve renal function, and inhibit inflammatory responses. SGLT-2 inhibitors can, therefore, simultaneously target multiple mechanisms of obesity-associated hypertension and may serve as an effective treatment for obesity-associated hypertension.

Influence of Perivascular Adipose Tissue on Microcirculation: A Link Between Hypertension and Obesity

Alterations in microcirculation play a crucial role in the pathogenesis of cardiovascular and metabolic disorders such as obesity and hypertension. The small resistance arteries of these patients show a typical remodeling, as indicated by an increase of media or total wall thickness to lumen diameter ratio that impairs organ flow reserve. The majority of blood vessels are surrounded by a fat depot which is termed perivascular adipose tissue (PVAT). In recent years, data from several studies have indicated that PVAT is an endocrine organ that can produce a variety of adipokines and cytokines, which may participate in the regulation of vascular tone, and the secretory profile varies with adipocyte phenotype and disease status. The PVAT of lean humans largely secretes the vasodilator adiponectin, which will act in a paracrine fashion to reduce peripheral resistance and improve nutrient uptake into tissues, thereby protecting against the development of hypertension and diabetes. In obesity, PVAT becomes enlarged and inflamed, and the bioavailability of adiponectin is reduced. The inevitable consequence is a rise in peripheral resistance with higher blood pressure. The interrelationship between obesity and hypertension could be explained, at least in part, by a cross-talk between microcirculation and PVAT. In this article, we propose an integrated pathophysiological approach of this relationship, in order to better clarify its role in obesity and hypertension, as the basis for effective and specific prevention and treatment.

Mechanisms and treatment of obesity-related hypertension-Part 1: Mechanisms

The prevalence of obesity has tripled over the past five decades. Obesity, especially visceral obesity, is closely related to hypertension, increasing the risk of primary (essential) hypertension by 65%-75%. Hypertension is a major risk factor for cardiovascular disease, the leading cause of death worldwide, and its prevalence is rapidly increasing following the pandemic rise in obesity. Although the causal relationship between obesity and high blood pressure (BP) is well established, the detailed mechanisms for such association are still under research. For more than 30 years sympathetic nervous system (SNS) and kidney sodium reabsorption activation, secondary to insulin resistance and compensatory hyperinsulinemia, have been considered as primary mediators of elevated BP in obesity. However, experimental and clinical data show that severe insulin resistance and hyperinsulinemia can occur in the absence of elevated BP, challenging the causal relationship between insulin resistance and hyperinsulinemia as the key factor linking obesity to hypertension. The purpose of Part 1 of this review is to summarize the available data on recently emerging mechanisms believed to contribute to obesity-related hypertension through increased sodium reabsorption and volume expansion, such as: physical compression of the kidney by perirenal/intrarenal fat and overactivation of the systemic/renal SNS and the renin-angiotensin-aldosterone system. The role of hyperleptinemia, impaired chemoreceptor and baroreceptor reflexes, and increased perivascular fat is also discussed. Specifically targeting these mechanisms may pave the way for a new therapeutic intervention in the treatment of obesity-related hypertension in the context of 'precision medicine' principles, which will be discussed in Part 2.

Effect of Obesity on Clinical Characteristics of Primary Aldosteronism Patients at Diagnosis and Postsurgical Response

CONTEXT

Patients with obesity have an overactivated renin-angiotensin-aldosterone system (RAAS) that is associated with essential hypertension. However, the influence of obesity in primary aldosteronism (PA) is unknown.

OBJECTIVE

We analyzed the effect of obesity on the characteristics of PA, and the association between obesity and RAAS components.

METHODS

A retrospective study was conducted of the Spanish PA Registry (SPAIN-ALDO Registry), which included patients with PA seen at 20 tertiary centers between 2018 and 2022. Differences between patients with and without obesity were analyzed.

RESULTS

A total of 415 patients were included; 189 (45.5%) with obesity. Median age was 55 years (range, 47.3-65.2 years) and 240 (58.4%) were male. Compared to those without obesity, patients with obesity had higher rates of diabetes mellitus, chronic kidney disease, obstructive apnea syndrome, left ventricular hypertrophy, prior cardiovascular events, higher means of systolic blood pressure, and required more antihypertensive drugs. Patients with PA and obesity also had higher values of serum glucose, glycated hemoglobin A1c, creatinine, uric acid, and triglycerides, and lower levels of high-density lipoprotein cholesterol. Levels of blood aldosterone (PAC) and renin were similar between patients with and without obesity. Body mass index was not correlated with PAC nor renin. The rates of adrenal lesions on imaging studies, as well as the rates of unilateral disease assessed by adrenal vein sampling or I-6β-iodomethyl-19-norcholesterol scintigraphy, were similar between groups.

CONCLUSION

Obesity in PA patients involves a worse cardiometabolic profile, and need for more antihypertensive drugs but similar PAC and renin levels, and rates of adrenal lesions and lateral disease than patients without obesity. However, obesity implicates a lower rate of hypertension cure after adrenalectomy.

Obesity and hypertension: Obesity medicine association (OMA) clinical practice statement (CPS) 2023

Background

This Obesity Medicine Association (OMA) Clinical Practice Statement (CPS) provides an overview of the mechanisms and treatment of obesity and hypertension.

Methods

The scientific support for this CPS is based upon published citations, clinical perspectives of OMA authors, and peer review by the Obesity Medicine Association leadership.

Results

Mechanisms contributing to obesity-related hypertension include unhealthful nutrition, physical inactivity, insulin resistance, increased sympathetic nervous system activity, renal dysfunction, vascular dysfunction, heart dysfunction, increased pancreatic insulin secretion, sleep apnea, and psychosocial stress. Adiposopathic factors that may contribute to hypertension include increased release of free fatty acids, increased leptin, decreased adiponectin, increased renin-angiotensin-aldosterone system activation, increased 11 beta-hydroxysteroid dehydrogenase type 1, reduced nitric oxide activity, and increased inflammation.

Conclusions

Increase in body fat is the most common cause of hypertension. Among patients with obesity and hypertension, weight reduction via healthful nutrition, physical activity, behavior modification, bariatric surgery, and anti-obesity medications mostly decrease blood pressure, with the greatest degree of weight reduction generally correlated with the greatest degree of blood pressure reduction.

Unique Gene Expression Signature in Periadrenal Adipose Tissue Identifies a High Blood Pressure Group in Patients With Cushing Syndrome

BACKGROUND

Cushing syndrome (CS) is a rare disease caused by excess cortisol levels with high cardiovascular morbidity and mortality. Hypertension in CS promotes hypercortisolism-associated cardiovascular events. Adipose tissue is a highly plastic tissue with most cell types strongly affected by the excess cortisol exposure. We hypothesized that the molecular and cellular changes of periadrenal adipose tissue in response to cortisol excess impact systemic blood pressure levels in patients with CS.

METHODS

We investigated gene expression signatures in periadrenal adipose tissue from patients with adrenal CS collected during adrenal surgery.

RESULTS

During active CS we observed a downregulation of gene programs associated with inflammation in periadrenal adipose tissue. In addition, we observed a clustering of the patients based on tissue gene expression profiles into 2 groups that differed in blood pressure levels (CS low blood pressure and CS high blood pressure). The 2 clusters showed significant differences in gene expression pattens of the renin-angiotensin-aldosterone-system. Renin was the strongest regulated gene compared with control patients and its expression correlated with increased blood pressure observed in our patients with CS. In the CS high blood pressure group, systemic renin plasma levels were suppressed indicative of an abnormal blood pressure associated with periadrenal adipose tissue renin-angiotensin-aldosterone-system activation.

CONCLUSIONS

Here, we show for the first time a relevant association of the local renin-angiotensin-aldosterone-system and systemic blood pressure levels in patients with CS. Patients from the CS high blood pressure group still had increased blood pressure levels after 6 months in remission, highlighting the importance of local tissue effects on long-term systemic effects observed in CS.

Association of the rs5186 polymorphism of the AGTR1 gene with decreased eGFR in patients with type 2 diabetes from Mexico City

BACKGROUND

Early biomarkers search for Diabetic Kidney Disease (DKD) in patients with Type 2 Diabetes Mellitus (T2DM), as genetic markers to identify vulnerable carriers of the disease even before Glomerular Filtration Rate (GFR) decline or microalbuminuria development, has been relevant during the last few years. The rs5186 (A116C) polymorphism of the Angiotensin II Receptor Type I gene (AGTR1), has been associated to multiple effects of renal injury risk, commonly detected in patients with Diabetes Mellitus (DM). It has been described that rs5186 could have an effect in stability proteins that assemble Angiotensin II Receptor Type I (AT1), modifying its action, which is why it should be considered as a risk factor for Chronic Kidney Disease (CKD), characterized by a GFR progressive reduction. Even though, the association between rs5186 AGTR1 gene polymorphism and DKD in patients with T2DM has been controversial, inconclusive, and even absent. This disputable issue might be as a result of association studies in which many and varied clinical phenotypes included are contemplated as CKD inductors and enhancers. Although, the sample sizes studied in patients with T2DM are undersized and did not have a strict inclusion criteria, lacking of biochemical markers or KDOQI classification, which have hindered its examination.

OBJECTIVE

The aim of our study was to establish an association between rs5186 AGTR1 gene polymorphism and GFR depletion, assessed as a risk factor to DKD development in patients with T2DM.

METHODS

We analyzed 297 not related patients with T2DM, divided into 221 controls (KDOQI 1) and 76 cases (KDOQI 2). Arterial pressure, anthropometric and biochemical parameters were measured. rs5186 of AGTR1 genotyping was performed by TaqMan assay real-time PCR method. Allele and genotype frequencies, and Hardy-Weinberg equilibrium were measured. Normality test for data distribution was analyzed by Shapiro-Wilk test, variable comparison by Student's t-test for continuous variables, and Chi-squared test for categorical variables; ANOVA test was used for mean comparison of more than two groups. Effect of rs5186 to DKD was estimated by multiple heritability adjustment models for risk variables of DKD. Statistical significance was indicated by p<0.05. Data was analyzed using Statistical Package STATA v11 software.

RESULTS

Dominant and Over-dominant models showed a likelihood ratio to GFR depletion of 1.89 (1.05-3.39, p=0.031) and 2.01 (1.08-3.73, p=0.023) in patients with T2DM. Risk factor increased to 2.54 (1.10-5.89) in women in Over-dominant model.

CONCLUSION

In clinical practice, most of nephropathies progress at a slow pace into a total breakdown of renal function, even asymptomatic. This is the first study, reporting that rs5186 polymorphism of AGTR1 gene contribution to GFR depletion, and this could be evaluated as a predisposing factor for DKD in patients with T2DM.

High-plasma soluble prorenin receptor is associated with vascular damage in male, but not female, mice fed a high-fat diet

Plasma soluble prorenin receptor (sPRR) displays sexual dimorphism and is higher in women with type 2 diabetes mellitus (T2DM). However, the contribution of plasma sPRR to the development of vascular complications in T2DM remains unclear. We investigated if plasma sPRR contributes to sex differences in the activation of the systemic renin-angiotensin-aldosterone system (RAAS) and vascular damage in a model of high-fat diet (HFD)-induced T2DM. Male and female C57BL/6J mice were fed either a normal fat diet (NFD) or an HFD for 28 wk to assess changes in blood pressure, cardiometabolic phenotype, plasma prorenin/renin, sPRR, and ANG II. After completing dietary protocols, tissues were collected from males to assess vascular reactivity and aortic reactive oxygen species (ROS). A cohort of male mice was used to determine the direct contribution of increased systemic sPRR by infusion. To investigate the role of ovarian hormones, ovariectomy (OVX) was performed at 32 wk in females fed either an NFD or HFD. Significant sex differences were found after 28 wk of HFD, where only males developed T2DM and increased plasma prorenin/renin, sPRR, and ANG II. T2DM in males was accompanied by nondipping hypertension, carotid artery stiffening, and aortic ROS. sPRR infusion in males induced vascular thickening instead of material stiffening caused by HFD-induced T2DM. While intact females were less prone to T2DM, OVX increased plasma prorenin/renin, sPRR, and systolic blood pressure. These data suggest that sPRR is a novel indicator of systemic RAAS activation and reflects the onset of vascular complications during T2DM regulated by sex.NEW & NOTEWORTHY High-fat diet (HFD) for 28 wk leads to type 2 diabetes mellitus (T2DM) phenotype, concomitant with increased plasma soluble prorenin receptor (sPRR), nondipping blood pressure, and vascular stiffness in male mice. HFD-fed female mice exhibiting a preserved cardiometabolic phenotype until ovariectomy revealed increased plasma sPRR and blood pressure. Plasma sPRR may indicate the status of systemic renin-angiotensin-aldosterone system (RAAS) activation and the onset of vascular complications during T2DM in a sex-dependent manner.

Renin-Angiotensin System: Updated Understanding and Role in Physiological and Pathophysiological States

The classical view of the renin-angiotensin system (RAS) is that of the circulating hormone pathway involved in salt and water homeostasis and blood pressure regulation. It is also involved in the pathogenesis of cardiac and renal disorders. This led to the creation of drugs blocking the actions of this classical pathway, which improved cardiac and renal outcomes. Our understanding of the RAS has significantly expanded with the discovery of new peptides involved in this complex pathway. Over the last two decades, a counter-regulatory or protective pathway has been discovered that opposes the effects of the classical pathway. Components of RAS are also implicated in the pathogenesis of obesity and its metabolic diseases. The continued discovery of newer molecules also provides novel therapeutic targets to improve disease outcomes. This article aims to provide an overview of an updated understanding of the RAS, its role in physiological and pathological processes, and potential novel therapeutic options from RAS for managing cardiorenal disorders, obesity, and related metabolic disorders.

Impact of Adipose Tissue Depot Harvesting Site on the Multilineage Induction Capacity of Male Rat Adipose-Derived Mesenchymal Stem Cells: An In Vitro Study

Recently, substantial attention has been paid toward adipose-derived mesenchymal stem cells (AdMSCs) as a potential therapy in tissue engineering and regenerative medicine applications. Rat AdMSCs (r-AdMSCs) are frequently utilized. However, the influence of the adipose depot site on the multilineage differentiation potential of the r-AdMSCs is still ambiguous. Hence, the main objective of this study was to explore the influence of the adipose tissue harvesting location on the ability of r-AdMSCs to express the stem-cell-related markers and pluripotency genes, as well as their differentiation capacity, for the first time. Herein, we have isolated r-AdMSCs from the inguinal, epididymal, peri-renal, and back subcutaneous fats. Cells were compared in terms of their phenotype, immunophenotype, and expression of pluripotency genes using RT-PCR. Additionally, we investigated their potential for multilineage (adipogenic, osteogenic, and chondrogenic) induction using special stains confirmed by the expression of the related genes using RT-qPCR. All cells could positively express stem cell marker CD 90 and CD 105 with no significant in-between differences. However, they did not express the hematopoietic markers as CD 34 and CD 45. All cells could be induced successfully. However, epididymal and inguinal cells presented the highest capacity for adipogenic and osteogenic differentiation (21.36-fold and 11.63-fold for OPN, 29.69-fold and 26.68-fold for BMP2, and 37.67-fold and 22.35-fold for BSP, respectively, in epididymal and inguinal cells (p < 0.0001)). On the contrary, the subcutaneous cells exhibited a superior potential for chondrogenesis over the other sites (8.9-fold for CHM1 and 5.93-fold for ACAN, (p < 0.0001)). In conclusion, the adipose tissue harvesting site could influence the differentiation capacity of the isolated AdMSCs. To enhance the results of their employment in various regenerative cell-based therapies, it is thus vital to take the collection site selection into consideration.

Leptin Increases: Physiological Roles in the Control of Sympathetic Nerve Activity, Energy Balance, and the Hypothalamic-Pituitary-Thyroid Axis

It is well established that decreases in plasma leptin levels, as with fasting, signal starvation and elicit appropriate physiological responses, such as increasing the drive to eat and decreasing energy expenditure. These responses are mediated largely by suppression of the actions of leptin in the hypothalamus, most notably on arcuate nucleus (ArcN) orexigenic neuropeptide Y neurons and anorexic pro-opiomelanocortin neurons. However, the question addressed in this review is whether the effects of increased leptin levels are also significant on the long-term control of energy balance, despite conventional wisdom to the contrary. We focus on leptin's actions (in both lean and obese individuals) to decrease food intake, increase sympathetic nerve activity, and support the hypothalamic-pituitary-thyroid axis, with particular attention to sex differences. We also elaborate on obesity-induced inflammation and its role in the altered actions of leptin during obesity.

State of the Art Review: Vascular Remodeling in Hypertension

Although the gold-standard method for the assessment of structural alteration in small resistance arteries is the evaluation of the MLR by micromyography in bioptic tissues, new, noninvasive techniques are presently under development, focusing mainly on the evaluation of WLR in retinal arterioles. These approaches represent a promising and interesting future perspective. Appropriate antihypertensive treatment is able to prevent the development of microvascular alterations or to induce their regression. Also, conductance arteries may be affected by a remodeling process in hypertension, and a cross-talk may exist between structural changes in the small and large arteries. In conclusion, the evaluation of microvascular structure is ready for clinical prime time, and it could, in the future, represent an evaluation to be performed in the majority of hypertensive patients, to better stratify cardiovascular risk and better evaluate the effects of antihypertensive therapy. However, for this purpose, we need a clear demonstration of the prognostic relevance of noninvasive measures of microvascular structure, in basal conditions and during treatment. Vascular remodeling may be frequently observed in hypertension, as well as in obesity and diabetes mellitus. An increased media to lumen ratio (MLR) or wall to lumen ratio (WLR) in microvessels is the hallmark of hypertension, and may impair organ flow reserve, being relevant in the maintenance and, probably, also in the progressive worsening of hypertensive disease, as well as in the development of hypertension-mediated organ damage/cardiovascular events. The molecular mechanisms underlying the development of vascular remodeling are only partly understood.

Contribution of RAS, ROS and COX-1-derived prostanoids to the contractile profile of perivascular adipose tissue in cafeteria diet-induced obesity

AIMS

Obesity can lead to the loss of the anticontractile properties of perivascular adipose tissue (PVAT). Given that cafeteria (CAF) diet reflects the variety of highly calorie and easily accessible foods in Western societies, contributing to obesity and metabolic disorders, we sought to investigate the impact of CAF diet on PVAT vasoactive profile and the involvement of renin-angiotensin system, oxidative stress, and cyclooxygenase pathway.

MAIN METHODS

Male Balb/c mice received standard or CAF diet for 4 weeks. Oral glucose tolerance and insulin sensitivity tests were performed, and fasting serum glucose, cholesterol and triglyceride parameters were determined. Vascular reactivity, fluorescence and immunofluorescence analyzes were carried out in intact thoracic aorta in the presence or absence of PVAT.

KEY FINDINGS

CAF diet was effective in inducing obesity and metabolic disorders, as demonstrated by increased body weight gain and adiposity index, hyperlipidemia, hyperglycemia, glucose intolerance and insulin insensitivity. Importantly, CAF diet led to a significant decrease in aortic contractility which was restored in the presence of PVAT, exhibiting therefore a contractile profile. The contractile effect of PVAT was associated with the activation of AT₁ receptor, reactive oxygen species, cyclooxygenase-1, thromboxane A₂ and prostaglandin E₂ receptors.

SIGNIFICANCE

These findings suggest that the contractile profile of PVAT involving the renin-angiotensin system activation, reactive oxygen species and cyclooxygenase-1 metabolites may be a protective compensatory adaptive response during early stage of CAF diet-induced obesity as an attempt to restore the impaired vascular contraction observed in the absence of PVAT, contributing to the maintenance of vascular tone.

The Role of (Pro)Renin Receptor in the Metabolic Syndrome

The prorenin receptor (PRR) is a complex multi-functional single transmembrane protein receptor that is ubiquitously expressed in organs and tissues throughout the body. PRR is involved in different cellular mechanisms that comprise the generation of Angiotensin II, the activation of Wnt/β-catenin signaling, the stimulation of ERK 1/2 pathway, and the proper functioning of the vacuolar H+-ATPase. Evidence supports the role of PRR and its soluble form, sPRR, in the classical features of the metabolic syndrome, including obesity, hypertension, diabetes, and disruption of lipid homeostasis. This review summarizes our current knowledge and highlights new advances in the pathophysiological function of PRR and sPRR in adipogenesis, adipocyte differentiation, lipolysis, glucose and insulin resistance, lipid homeostasis, energy metabolism, and blood pressure regulation.

Temporal patterns of alterations in obesity index, lipid profile, renal function and blood pressure during the development of hypertension in male, but not female, rats fed a moderately high-fat diet

CONTEXT

Male Sprague-Dawley rats consuming a moderately high-fat (MHF)-diet diverge into obesity-prone (OP) with hypertension and obesity-resistant.

OBJECTIVES

To study the temporal inter-relationships between body-weight, obesity-index, plasma lipid-profile, renal functional parameters and systolic-pressure alterations during 10-weeks feeding MHF or normal diet to male and female rats.

METHODS

Body-weight, obesity-index and systolic-pressure were measured weekly, while metabolic-cage and blood-sampling protocols were performed every other week. After 10-weeks, renal excretory responses to acute salt-loading and renal autoregulation were examined.

RESULTS

The male-OP group had progressively increased body-weight, plasma-triglyceride and systolic-pressure from Weeks 2, 4 and 5, respectively, lower renal sodium-excretion at weeks 4-8 and finally, delayed excretory response to salt-loading and rightward and downward shifts in renal autoregulatory curves compared to all other groups.

CONCLUSION

Feeding the MHF-diet in male-OP rats led to a greater weight-gain and adiposity followed by the development of atherogenic-hyperlipidaemia and persistently impaired pressure-natriuresis to induce hypertension.

Angiotensin II Promotes White Adipose Tissue Browning and Lipolysis in Mice

Emerging evidence has revealed that all components of the renin-angiotensin system (RAS) are present in adipose tissue. Angiotensin II (Ang II), the major bioactive component of the RAS, has been recognized as an adipokine involved in regulating energy homeostasis. However, the precise role of Ang II in white adipose tissue (WAT) remodeling remains to be elucidated. In this present study, C57BL/C male mice were continuously infused with different doses of Ang II (1.44 mg/kg/d or 2.5 mg/kg/d) or saline for 2 weeks and treated with or without the Ang II type 1 receptor blocker valsartan. H&E staining and immunohistochemistry were conducted to investigate the white-to-brown fat conversion. The level of serum total cholesterol (TC), triglyceride (TG), low-density lipoprotein cholesterol (LDL-C), and high-density lipoprotein cholesterol (HDL-C) was measured. RNA sequencing was employed to explore the differentially expressed genes and their enriched pathways between control and Ang II groups. Our results showed that Ang II substantially resulted in loss of body weight and fat mass. Most importantly, Ang II treatment induced WAT browning in mice, which was partially attenuated by valsartan treatment. Furthermore, Ang II perturbed the serum lipid profiles. Ang II treatment elevated serum levels of TC, TG, LDL-C, and HDL-C in mice. Mechanistically, thermogenesis, cell respiration, and lipid metabolism-associated mRNAs showed significantly increased expression profiling in Ang II-treated WATs compared with control WATs. Moreover, we found that Ang II treatment enhanced AMPK phosphorylation in adipocytes. Therefore, Ang II promotes WAT browning and lipolysis via activating the AMPK signaling pathway.

Modulation of Vasomotor Function by Perivascular Adipose Tissue of Renal Artery Depends on Severity of Arterial Dysfunction to Nitric Oxide and Severity of Metabolic Parameters

Perivascular adipose tissue (PVAT) enhances vascular relaxation of mesenteric arteries in SHRSP.Z-Leprfa/IzmDmcr rats (SPZF), a metabolic syndrome model. We investigated and compared the effects of PVAT on the renal artery in SPZF with those on SHR/NDmcr-cp rats (CP). Renal arteries with and without PVAT were isolated from 23-week-old SPZF and CP. The effects of PVAT on acetylcholine- and nitroprusside-induced relaxation were examined using bioassays with phenylephrine-contracted arterial rings. Acetylcholine-induced relaxations without PVAT in SPZF and CP were 0.7- and 0.5-times lower in females than in males, respectively. In the presence of PVAT, acetylcholine-induced relaxations increased 1.4- and 2-times in male and female CP, respectively, but did not differ in SPZF. Nitroprusside-induced relaxation with and without PVAT was 0.7-times lower in female than in male SPZF but did not differ in CP. Angiotensin-II type-1 receptor (AT1R)/AT1R-associated protein mRNA ratios were lower in CP than in the SPZF and negatively correlated with the difference in arterial relaxation with and without PVAT. The effects of renal artery PVAT differed between the SPZF and CP groups. Higher levels of enhanced AT1R activity in SPZF PVAT may drive these differences by impairing the vascular smooth muscle responses to nitric oxide.

Angiotensin II Inhibits Insulin Receptor Signaling in Adipose Cells

Angiotensin II (Ang II) is a critical regulator of insulin signaling in the cardiovascular system and metabolic tissues. However, in adipose cells, the regulatory role of Ang II on insulin actions remains to be elucidated. The effect of Ang II on insulin-induced insulin receptor (IR) phosphorylation, Akt activation, and glucose uptake was examined in 3T3-L1 adipocytes. In these cells, Ang II specifically inhibited insulin-stimulated IR and insulin receptor substrate-1 (IRS-1) tyrosine-phosphorylation, Akt activation, and glucose uptake in a time-dependent manner. These inhibitory actions were associated with increased phosphorylation of the IR at serine residues. Interestingly, Ang II-induced serine-phosphorylation of IRS was not detected, suggesting that Ang II-induced desensitization begins from IR regulation itself. PKC inhibition by BIM I restored the inhibitory effect of Ang II on insulin actions. We also found that Ang II promoted activation of several PKC isoforms, including PKCα/βI/βII/δ, and its association with the IR, particularly PKCβII, showed the highest interaction. Finally, we also found a similar regulatory effect of Ang II in isolated adipocytes, where insulin-induced Akt phosphorylation was inhibited by Ang II, an effect that was prevented by PKC inhibitors. These results suggest that Ang II may lead to insulin resistance through PKC activation in adipocytes.

Precision Nephrology in Patients with Diabetes and Chronic Kidney Disease

Diabetes is the leading cause of kidney failure and specifically, diabetic kidney disease (DKD) occurs in up to 30% of all diabetic patients. Kidney disease attributed to diabetes is a major contributor to the global burden of the disease in terms of clinical and socio-economic impact, not only because of the risk of progression to End-Stage Kidney Disease (ESKD), but also because of the associated increase in cardiovascular (CV) risk. Despite the introduction of novel treatments that allow us to reduce the risk of future outcomes, a striking residual cardiorenal risk has been reported. This risk is explained by both the heterogeneity of DKD and the individual variability in response to nephroprotective treatments. Strategies that have been proposed to improve DKD patient care are to develop novel biomarkers that classify with greater accuracy patients with respect to their future risk (prognostic) and biomarkers that are able to predict the response to nephroprotective treatment (predictive). In this review, we summarize the principal prognostic biomarkers of type 1 and type 2 diabetes and the novel markers that help clinicians to individualize treatments and the basis of the characteristics that predict an optimal response.

Perivascular Adipose Tissue Compensation for Endothelial Dysfunction in the Superior Mesenteric Artery of Female SHRSP.Z-<i>Lepr</i>^<i>fa</i>/IzmDmcr Rats

Regulation of arterial tone by perivascular adipose tissue (PVAT) differs between sexes. In male SHRSP.Z-<i>Lepr</i>^<i>fa</i>/IzmDmcr rats (SHRSP.ZF), PVAT exerts a compensatory relaxation effect for the loss of endothelium-mediated vasorelaxation, which occurs during the early stages of metabolic syndrome. However, this effect deteriorates by 23 weeks of age. Here, therefore, we compared the effects of PVAT in female and male SHRSP.ZF. Acetylcholine-induced relaxation in superior mesenteric artery without PVAT did not differ between 23-week-old females and males. However, the presence of PVAT enhanced relaxation in 23-week-old females, but not in males. The mRNA levels of angiotensin II type 1 receptor (AT1R) in PVAT did not differ between sexes, but AT1R-associated protein (ATRAP) and apelin levels were higher in females than in males. We observed a positive relationship between differences in artery relaxation with and without PVAT and ATRAP or apelin mRNA levels. In 30-week-old females, PVAT-enhanced relaxation disappeared, and mRNA levels of AT1R increased, while apelin levels decreased compared to 23-week-old females. These results demonstrated that in SHRSP.ZF, PVAT compensation for endothelium dysfunction extended to older ages in females than in males. Apelin and AT1R/ATRAP expression in PVAT may be predictors of favorable effects.

Sex influences the effect of adiposity on arterial stiffness and renin‐angiotensin aldosterone system activity in young adults

Introduction

Methods

Results

Conclusion

Renin-angiotensin system modulation through enalapril and/or exercise training improves visceral adiposity in obese mice

INTRODUCTION

Obesity-related metabolic diseases occur as a result of disruptions in white adipose tissue (WAT) plasticity, especially through visceral fat accumulation and adipocyte hypertrophy. This study aimed to evaluate the impact of renin-angiotensin system (RAS) and bradykinin receptors modulation by enalapril treatment and/or exercise training on WAT morphology and related deleterious outcomes.

METHODS

Male C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At the 8th week, HF-fed animals were divided into sedentary (HF), enalapril treatment (HF-E), exercise training (HF-T), and enalapril treatment plus exercise training (HF-ET) groups. Following the experimental protocol, body mass gain, adiposity index, insulin resistance, visceral WAT morphometry, renin-angiotensin system, and bradykinin receptors were evaluated.

RESULTS

The HF group displayed increased adiposity, larger visceral fat mass, and adipocyte hypertrophy, which was accompanied by insulin resistance, overactivation of Ang II/AT1R arm, and favoring of B1R in bradykinin receptors profile. All interventions ameliorated visceral adiposity and related outcomes by favoring the Ang 1-7/MasR arm and the B2R expression in B1R/B2R ratio. However, combined therapy additively reduced Ang II/Ang 1-7 ratio.

CONCLUSION

Our results suggest that Ang 1-7/MasR arm and B2R activation might be relevant targets in the treatment of visceral obesity.

Exploring the Relationship of Perivascular Adipose Tissue Inflammation and the Development of Vascular Pathologies

Initially thought to only provide mechanical support for the underlying blood vessels, perivascular adipose tissue (PVAT) has now emerged as a regulator of vascular function. A healthy PVAT exerts anticontractile and anti-inflammatory actions on the underlying vasculature via the release of adipocytokines such as adiponectin, nitric oxide, and omentin. However, dysfunctional PVAT produces more proinflammatory adipocytokines such as leptin, resistin, interleukin- (IL-) 6, IL-1β, and tumor necrosis factor-alpha, thus inducing an inflammatory response that contributes to the pathogenesis of vascular diseases. In this review, current knowledge on the role of PVAT inflammation in the development of vascular pathologies such as atherosclerosis and hypertension was discussed.

Renin-angiotensin system: Basic and clinical aspects-A general perspective

The renin–angiotensin system (RAS) is one of the most complex hormonal regulatory systems, involving several organs that interact to regulate multiple body functions. The study of this system initially focused on investigating its role in the regulation of both cardiovascular function and related pathologies. From this approach, pharmacological strategies were developed for the treatment of cardiovascular diseases. However, new findings in recent decades have suggested that the RAS is much more complex and comprises two subsystems, the classic RAS and an alternative RAS, with antagonistic effects that are usually in equilibrium. The classic system is involved in pathologies where inflammatory, hypertrophic and fibrotic phenomena are common and is related to the development of chronic diseases that affect various body systems. This understanding has been reinforced by the evidence that local renin–angiotensin systems exist in many tissue types and by the role of the RAS in the spread and severity of COVID-19 infection, where it was discovered that viral entry into cells of the respiratory system is accomplished through binding to angiotensin-converting enzyme 2, which is present in the alveolar epithelium and is overexpressed in patients with chronic cardiometabolic diseases. In this narrative review, preclinical and clinical aspects of the RAS are presented and topics for future research are discussed some aspects are raised that should be clarified in the future and that call for further investigation of this system.

Comparative Proteomic Analysis of tPVAT during Ang II Infusion

Perivascular adipose tissue (PVAT) homeostasis plays an important role in maintaining vascular function, and PVAT dysfunction may induce several pathophysiological situations. In this study, we investigated the effect and mechanism of the local angiotensin II (Ang II) on PVAT. High-throughput comparative proteomic analysis, based on TMT labeling combined with LC-MS/MS, were performed on an in vivo Ang II infusion mice model to obtain a comprehensive view of the protein ensembles associated with thoracic PVAT (tPVAT) dysfunction induced by Ang II. In total, 5037 proteins were confidently identified, of which 4984 proteins were quantified. Compared with the saline group, 145 proteins were upregulated and 146 proteins were downregulated during Ang II-induced tPVAT pathogenesis. Bioinformatics analyses revealed that the most enriched GO terms were annotated as gene silencing, monosaccharide binding, and extracellular matrix. In addition, some novel proteins, potentially associated with Ang II infusion, were identified, such as acyl-CoA carboxylase α, very long-chain acyl-CoA synthetase (ACSVL), uncoupling protein 1 (UCP1), perilipin, RAS protein-specific guanine nucleotide-releasing factor 2 (RasGRF2), and hypoxia inducible factor 1α (HIF-1α). Ang II could directly participate in the regulation of lipid metabolism, transportation, and adipocyte differentiation by affecting UCP1 and perilipin. Importantly, the key KEGG pathways were involved in fatty acid biosynthesis, FABP3-PPARα/γ, RasGRF2-ERK-HIF-1α, RasGRF2-PKC-HIF-1α, and STAT3-HIF-1α axis. The present study provided the most comprehensive proteome profile of mice tPVAT and some novel insights into Ang II-mediated tPVAT dysfunction and will be helpful for understanding the possible relationship between local RAS activation and PVAT dysfunction.

Ovariectomy Causes Degeneration of Perivascular Adipose Tissue

Women are more resistant than men to the development of vascular diseases. However, menopause is a factor leading to deterioration of female vascular integrity, and it is reported that the risk of vascular diseases such as atherosclerosis and abdominal aortic aneurysm is increased in postmenopausal women. Although it is suggested that perivascular adipose tissue (PVAT) is deeply involved in the increased risk of vascular disease development, the effect of menopause on PVAT integrity is unknown. In this study, we aimed to elucidate the effect of menopause on PVAT in ovariectomized (OVX) rats. PVAT was divided into 4 regions based on characteristics. Hypertrophy and increased inflammation of adipocytes in the PVAT were observed in the OVX group, but the effects of OVX were different for each region. OVX induced matrix metalloproteinase (MMP) -9 which degrade extracellular matrix such as elastin and collagen fibers in PVAT. Degeneration of the arterial fibers of the thoracic and abdominal aorta were observed in the OVX group. These results indicate that OVX can cause dysfunction of PVAT which can cause degradation of arterial fibers. Appropriate management of PVAT may play an important role in the prevention and treatment of diseases originating from ovarian hypofunction.

Renin-angiotensin system: Basic and clinical aspects-A general perspective

The renin–angiotensin system (RAS) is one of the most complex hormonal regulatory systems, involving several organs that interact to regulate multiple body functions. The study of this system initially focused on investigating its role in the regulation of both cardiovascular function and related pathologies. From this approach, pharmacological strategies were developed for the treatment of cardiovascular diseases. However, new findings in recent decades have suggested that the RAS is much more complex and comprises two subsystems, the classic RAS and an alternative RAS, with antagonistic effects that are usually in equilibrium. The classic system is involved in pathologies where inflammatory, hypertrophic and fibrotic phenomena are common and is related to the development of chronic diseases that affect various body systems. This understanding has been reinforced by the evidence that local renin–angiotensin systems exist in many tissue types and by the role of the RAS in the spread and severity of COVID-19 infection, where it was discovered that viral entry into cells of the respiratory system is accomplished through binding to angiotensin-converting enzyme 2, which is present in the alveolar epithelium and is overexpressed in patients with chronic cardiometabolic diseases. In this narrative review, preclinical and clinical aspects of the RAS are presented and topics for future research are discussed some aspects are raised that should be clarified in the future and that call for further investigation of this system.

Inflammation in Metabolic Cardiomyopathy

Overlapping pandemics of lifestyle-related diseases pose a substantial threat to cardiovascular health. Apart from coronary artery disease, metabolic disturbances linked to obesity, insulin resistance and diabetes directly compromise myocardial structure and function through independent and shared mechanisms heavily involving inflammatory signals. Accumulating evidence indicates that metabolic dysregulation causes systemic inflammation, which in turn aggravates cardiovascular disease. Indeed, elevated systemic levels of pro-inflammatory cytokines and metabolic substrates induce an inflammatory state in different cardiac cells and lead to subcellular alterations thereby promoting maladaptive myocardial remodeling. At the cellular level, inflammation-induced oxidative stress, mitochondrial dysfunction, impaired calcium handling, and lipotoxicity contribute to cardiomyocyte hypertrophy and dysfunction, extracellular matrix accumulation and microvascular disease. In cardiometabolic patients, myocardial inflammation is maintained by innate immune cell activation mediated by pattern recognition receptors such as Toll-like receptor 4 (TLR4) and downstream activation of the NLRP3 inflammasome and NF-κB-dependent pathways. Chronic low-grade inflammation progressively alters metabolic processes in the heart, leading to a metabolic cardiomyopathy (MC) phenotype and eventually to heart failure with preserved ejection fraction (HFpEF). In accordance with preclinical data, observational studies consistently showed increased inflammatory markers and cardiometabolic features in patients with HFpEF. Future treatment approaches of MC may target inflammatory mediators as they are closely intertwined with cardiac nutrient metabolism. Here, we review current evidence on inflammatory processes involved in the development of MC and provide an overview of nutrient and cytokine-driven pro-inflammatory effects stratified by cell type.

A Comparative Study of the Effect of Anatomical Site on Multiple Differentiation of Adipose-Derived Stem Cells in Rats

Mesenchymal stem cells (MSCs) derived from adipose tissue are evolved into various cell-based regenerative approaches. Adipose-derived stem cells (ASCs) isolated from rats are commonly used in tissue engineering studies. Still, there is a gap in knowledge about how the harvest locations influence and guide cell differentiation. This study aims to investigate how the harvesting site affects stem-cell-specific surface markers expression, pluripotency, and differentiation potential of ASCs in female Sprague Dawley rats. ASCs were extracted from the adipose tissue of the peri-ovarian, peri-renal, and mesenteric depots and were compared in terms of cell morphology. MSCs phenotype was validated by cell surfaces markers using flow cytometry. Moreover, pluripotent gene expression of Oct4, Nanog, Sox2, Rex-1, and Tert was evaluated by reverse transcriptase-polymerase chain reaction (RT-PCR). ASCs multipotency was evaluated by specific histological stains, and the results were confirmed by quantitative polymerase chain reaction (RT-qPCR) expression analysis of specific genes. There was a non-significant difference detected in the cell morphology and immunophenotype between different harvesting sites. ASCs from multiple locations were significantly varied in their capacity to differentiate into adipocytes, osteoblastic cells, and chondrocytes. To conclude, depot selection is a critical element that should be considered when using ASCs in tissue-specific cell-based regenerative therapies research.

Angiotensin-converting enzyme inhibitors versus angiotensin II receptor blockers on insulin sensitivity in hypertensive patients: A meta-analysis of randomized controlled trials

Introduction

This meta-analysis aimed to summarize the available evidence to compare angiotensin-converting enzyme (ACE) inhibitors with angiotensin II receptor blockers (ARBs) on improving insulin sensitivity in hypertensive patients.

Methods

Randomized controlled trials (RCTs) comparing ACE inhibitors versus ARBs published with outcomes on homeostasis model assessment of IR (HOMA-IR), glucose infusion rate (GIR), the quantitative insulin sensitivity check index (QUICKI), insulin sensitivity index (ISI) composite, fasting plasma glucose (FPG), fasting plasma insulin (FPI), systolic blood pressure (SBP), and diastolic blood pressure (DBP) were searched through 5 databases. Data were searched from their inception to July 5, 2020. Stata 14.0 was used to perform the meta-analysis.

Results

Eleven RCTs (n = 1015) were included in this meta-analysis. Pooled analysis of studies showed no significant difference in HOMA-IR between ARBs and ACE inhibitors (WMD = -0.09, 95% CI: -0.69 to 0.50, P = 0.755); however, subgroup analysis of therapeutic duration showed a significant difference in HOMA-IR between ARBs and ACE inhibitors among the long-term intervention subgroup (>12 weeks) (WMD = 0.41, 95% CI: 0.06 to 0.76, P = 0.022) and hypertensive patients with diabetes mellitus subgroup (WMD = 0.55, 95% CI: 0.49 to 0.61, P < 0.001); results showed no significant difference between ARBs and ACE inhibitors on QUICKI score (WMD = -0.00, 95% CI: -0.03 to 0.03, P = 0.953) in hypertensive patients; however, the efficacy of ACE inhibitors on improving GIR and ISI composite was significantly better than that of ARBs (WMD = -1.09, 95% CI: -1.34 to -0.85, P < 0.001; WMD = -0.80, 95% CI: -1.24 to -0.36, P < 0.001, respectively). Furthermore, no significant differences were noted on FPG (WMD = 0.72, 95% CI: -1.39 to 2.83, P = 0.505), FPI (WMD = -0.48, 95% CI: -1.60 to 0.64, P = 0.398), SBP (WMD = -0.65, 95% CI: -1.76 to 0.46, P = 0.254), and DBP (WMD = -0.30, 95% CI: -1.70 to 1.10, P = 0.675) between ARBs and ACE inhibitors.

Conclusion

Results from this meta-analysis showed that ACE inhibitors resulted in more effective improvement of HOMA-IR compared with ARBs among the long-term intervention and hypertensive patients with DM subgroup; furthermore, the efficacy of ACE inhibitors on improving GIR and ISI composite was significantly better than that of ARBs in hypertensive patients. However, ARBs had no significant difference in QUICKI score, FPG, FPI, SBP, and DBP compared with ACE inhibitors. Larger and better-designed studies are needed to further verify this conclusion.

Impact of adipose tissue in chronic kidney disease development (Review)

Obesity is a worldwide pandemic health issue. Obesity is associated with the pathogenesis of type 2 diabetes, hypertension, dyslipidemia, cardiovascular diseases, cancer, and kidney diseases. This systemic disease can affect the kidneys by two mechanisms: Indirectly through diabetes mellitus (DM) and hypertension and directly through adipokines secreted by adipose tissue. Obesity is a risk factor for chronic kidney disease (CKD), which is associated with an increased risk of morbidity and mortality among the adult population. Increased visceral adipose tissue leads to renal glomerular hyperfiltration and hyperperfusion, which may lead to glomerular hypertrophy, proteinuria, and CKD development. Adipokines are hormones produced by fat tissue. They are involved in energy homeostasis, sugar and fat metabolism, reproduction, immunity, and thermogenesis control. Hormones and cytokines secreted by adipose tissue contribute to the development and progression of CKD. Decreased serum or urinary adiponectin levels are specific in diabetic and non-diabetic CKD patients, while leptin presents increased levels, and both are associated with the development of glomerulopathy. Excessive adipose tissue is associated with inflammation, oxidative stress (OS), insulin resistance and activation of the renin angiotensin-aldosterone system (RAAS). Therefore, adipose tissue dysfunction plays an important role in the development of CKD.

Obesity as a Risk Factor for Severe COVID-19 and Complications: A Review

Emerging data suggest that obesity is a major risk factor for the progression of major complications such as acute respiratory distress syndrome (ARDS), cytokine storm and coagulopathy in COVID-19. Understanding the mechanisms underlying the link between obesity and disease severity as a result of SARS-CoV-2 infection is crucial for the development of new therapeutic interventions and preventive measures in this high-risk group. We propose that multiple features of obesity contribute to the prevalence of severe COVID-19 and complications. First, viral entry can be facilitated by the upregulation of viral entry receptors, like angiotensin-converting enzyme 2 (ACE2), among others. Second, obesity-induced chronic inflammation and disruptions of insulin and leptin signaling can result in impaired viral clearance and a disproportionate or hyper-inflammatory response, which together with elevated ferritin levels can be a direct cause for ARDS and cytokine storm. Third, the negative consequences of obesity on blood coagulation can contribute to the progression of thrombus formation and hemorrhage. In this review we first summarize clinical findings on the relationship between obesity and COVID-19 disease severity and then further discuss potential mechanisms that could explain the risk for major complications in patients suffering from obesity.

The Tissue Renin-Angiotensin System and Its Role in the Pathogenesis of Major Human Diseases: Quo Vadis?

Evidence has arisen in recent years suggesting that a tissue renin-angiotensin system (tRAS) is involved in the progression of various human diseases. This system contains two regulatory pathways: a pathological pro-inflammatory pathway containing the Angiotensin Converting Enzyme (ACE)/Angiotensin II (AngII)/Angiotensin II receptor type 1 (AGTR1) axis and a protective anti-inflammatory pathway involving the Angiotensin II receptor type 2 (AGTR2)/ACE2/Ang1–7/MasReceptor axis. Numerous studies reported the positive effects of pathologic tRAS pathway inhibition and protective tRAS pathway stimulation on the treatment of cardiovascular, inflammatory, and autoimmune disease and the progression of neuropathic pain. Cell senescence and aging are known to be related to RAS pathways. Further, this system directly interacts with SARS-CoV 2 and seems to be an important target of interest in the COVID-19 pandemic. This review focuses on the involvement of tRAS in the progression of the mentioned diseases from an interdisciplinary clinical perspective and highlights therapeutic strategies that might be of major clinical importance in the future.

The impact of reactive oxygen species in the development of cardiometabolic disorders: a review

Oxidative stress, an alteration in the balance between reactive oxygen species (ROS) generation and antioxidant buffering capacity, has been implicated in the pathogenesis of cardiometabolic disorders (CMD). At physiological levels, ROS functions as signalling mediators, regulates various physiological functions such as the growth, proliferation, and migration endothelial cells (EC) and smooth muscle cells (SMC); formation and development of new blood vessels; EC and SMC regulated death; vascular tone; host defence; and genomic stability. However, at excessive levels, it causes a deviation in the redox state, mediates the development of CMD. Multiple mechanisms account for the rise in the production of free radicals in the heart. These include mitochondrial dysfunction and uncoupling, increased fatty acid oxidation, exaggerated activity of nicotinamide adenine dinucleotide phosphate oxidase (NOX), reduced antioxidant capacity, and cardiac metabolic memory. The purpose of this study is to discuss the link between oxidative stress and the aetiopathogenesis of CMD and highlight associated mechanisms. Oxidative stress plays a vital role in the development of obesity and dyslipidaemia, insulin resistance and diabetes, hypertension via various mechanisms associated with ROS-led inflammatory response and endothelial dysfunction.

ACE2 and energy metabolism: the connection between COVID-19 and chronic metabolic disorders

The renin-angiotensin system (RAS) has currently attracted increasing attention due to its potential function in regulating energy homeostasis, other than the actions on cellular growth, blood pressure, fluid, and electrolyte balance. The existence of RAS is well established in metabolic organs, including pancreas, liver, skeletal muscle, and adipose tissue, where activation of angiotensin-converting enzyme (ACE) - angiotensin II pathway contributes to the impairment of insulin secretion, glucose transport, fat distribution, and adipokines production. However, the activation of angiotensin-converting enzyme 2 (ACE2) - angiotensin (1-7) pathway, a novel branch of the RAS, plays an opposite role in the ACE pathway, which could reverse these consequences by improving local microcirculation, inflammation, stress state, structure remolding, and insulin signaling pathway. In addition, new studies indicate the protective RAS arm possesses extraordinary ability to enhance brown adipose tissue (BAT) activity and induces browning of white adipose tissue, and consequently, it leads to increased energy expenditure in the form of heat instead of ATP synthesis. Interestingly, ACE2 is the receptor of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), which is threating public health worldwide. The main complications of SARS-CoV-2 infected death patients include many energy metabolism-related chronic diseases, such as diabetes. The specific mechanism leading to this phenomenon is largely unknown. Here, we summarize the latest pharmacological and genetic tools on regulating ACE/ACE2 balance and highlight the beneficial effects of the ACE2 pathway axis hyperactivity on glycolipid metabolism, as well as the thermogenic modulation.

Relationship of Cardiac Autonomic Modulation with Cardiovascular Parameters in Adults, According to Body Mass Index and Physical Activity

This study aimed to analyze the relationship between cardiac autonomic modulation (CAM) and cardiovascular parameters (blood pressure and resting heart rate) in a sample of 256 adults, grouped by body mass index and sufficient moderate-to-vigorous physical activity (≥150 min/week). The sample showed different cardiovascular parameters and CAM according to body mass index, but not according to physical activity. Adults who are overweight and physically active presented higher relationship between CAM and blood pressure than those who are insufficiently active, similarly to normal weight groups. Recommended levels of physical activity may play an important role in the relationship of HRV with cardiovascular parameters in overweight adults, regardless of sex, age, socioeconomic level, and central fat. Trial registration: Registered at ClinicalTrials.gov (NCT03986879). Graphical abstract.

Enlarged adipocytes from subcutaneous vs. visceral adipose tissue differentially contribute to metabolic dysfunction and atherogenic risk of patients with obesity

Morphological characteristics and source of adipose tissue as well as adipokines may increase cardiometabolic risk. This study aimed to explore whether adipose tissue characteristics may impact metabolic and atherogenic risks. Subcutaneous Adipose Tissue (SAT), Visceral Adipose Tissue (VAT) and peripheral blood were obtained from obese patients submitted to bariatric surgery. Adipose tissue (morphometry), plasma adiponectin, TNF-α, resistin (multiplexing) and biochemical chemistry were analyzed; as well as endothelial dysfunction (Flow Mediated Dilation, FMD) and atherogenesis (Carotid Intima Media Thickness, CIMT). Subgroups divided by adipocyte size and source were compared; as well as correlation and multivariate analysis. Sixty patients 36.6% males, aged 44 years-old, BMI 46.7 kg/m² were included. SAT's adipocytes showed a lower range of size expandability than VAT's adipocytes. Independent from their source, larger adipocytes were associated with higher glucose, lower adiponectin and higher CIMT. Particularly, larger adipocytes from SAT were associated with higher blood pressure, lower insulin and HDL-cholesterol; and showed positive correlation with glucose, Hb_A1c, systolic/diastolic values, and negatively correlated with insulin and adiponectin. VAT's larger adipocytes particularly associated with lower resistin and lower FMD values. Gender and Diabetes Mellitus significantly impacted the relation of adipocyte size/source with the metabolic and atherogenic risk. Multivariable analysis suggested hypertension-resistin-Hb_A1c interactions associated with SAT's larger adipocytes; whereas potential insulin-adiponectin associations were observed for VAT's larger adipocytes. Adipocyte morphology and source are differentially related with cardiometabolic and atherogenic risk in population with obesity, which are potentially affected by gender and Diabetes Mellitus.

Update on the Crosstalk Between Adipose Tissue and Mineral Balance in General Population and Chronic Kidney Disease

Adipose tissue is nowadays considered as a major endocrine organ, which apart from controlling lipid metabolism, displays a significant role in energy expenditure, food intake and in the regulation of various systemic physiological processes. Adipose derived pro-inflammatory cytokines and adipokines, particularly leptin and adiponectin, provide inter-communication of adipose tissue with various metabolic pathways, ultimately resulting in a complex network of interconnected organ systems. Recent clinical and experimental research has been focused on exploring the direct interaction between adipokine profile and elements of mineral metabolism, including parathormone (PTH), fibroblast growth factor-23 (FGF23) and calcitriol. The emerging crosstalk between adipose tissue and calcium and phosphorus homeostasis suggests that metabolic disorders from one system may directly affect the other and vice versa. It is current knowledge that fat metabolism disturbance, commonly encountered in obese individuals, influences the expression of calciotriopic hormones in general population, while various clinical trials attempting to successfully achieve body fat loss by modulating mineral profile have been published. In chronic kidney disease (CKD) state, there is an increasing evidence suggesting that mineral disorders, influence adipose tissue and linked endocrine function. On the contrary, the impact of disturbed fat metabolism on CKD related mineral disorders has been also evocated in clinical studies. Recognizing the pathogenetic mechanisms of communication between adipose tissue and mineral balance is critical for understanding the effects of metabolic perturbations from the one system to the other and for identifying possible therapeutic targets in case of disrupted homeostasis in one of the two connected systems. To that end, this review aims to enlighten the recent advances regarding the interplay between mineral metabolism, fat mass and adipokine profile, based on in vitro, in vivo and clinical studies, in general population and in the course of CKD.

Augmented transcripts of kidney injury markers and renin angiotensin system in urine samples of overweight young adults

Obesity has been firmly established as a major risk factor for common disease states including hypertension, type 2 diabetes mellitus, and chronic kidney disease. Increased body mass index (BMI) contributes to the activation of both the systemic and intra-tubular renin angiotensin systems (RAS), which are in turn associated with increased blood pressure (BP) and kidney damage. In this cross-sectional study, 43 subjects of normal or increased body weight were examined in order to determine the correlation of BMI or body fat mass (BFM) with blood pressure, fasting blood glucose (FBG), and urinary kidney injury markers such as interleukin-18 (IL-18), connective tissue growth factor (CTGF), neutrophil gelatinase-associated lipocalin, and kidney injury molecule-1 (KIM-1). Our results showed that: (1) subjects with increased body weight showed significantly higher BP, BFM, total body water and metabolic age; (2) BMI was positively correlated to both systolic (R² = 0.1384, P = 0.01) and diastolic BP (R² = 0.2437, P = 0.0008); (3) BFM was positively correlated to DBP (R² = 0.1232, P = 0.02) and partially correlated to urine protein (R² = 0.047, P = 0.12) and FBG (R² = 0.07, P = 0.06); (4) overweight young adults had higher urinary mRNA levels of renin, angiotensinogen, IL-18 and CTGF. These suggest that BMI directly affects BP, kidney injury markers, and the activation of the intra-tubular RAS even in normotensive young adults. Given that BMI measurements and urine analyses are non-invasive, our findings may pave the way to developing a new and simple method of screening for the risk of chronic kidney disease in adults.

The Pivotal Role of Adipocyte-Na K peptide in Reversing Systemic Inflammation in Obesity and COVID-19 in the Development of Heart Failure

This review summarizes data from several laboratories that have demonstrated a role of the Na/K-ATPase, specifically its α1 subunit, in the generation of reactive oxygen species (ROS) via the negative regulator of Src. Together with Src and other signaling proteins, the Na/K-ATPase forms an oxidant amplification loop (NKAL), amplifies ROS, and participates in cytokines storm in obesity. The development of a peptide fragment of the α1 subunit, NaKtide, has been shown to negatively regulate Src. Several groups showed that the systemic administration of the cell permeable modification of NaKtide (pNaKtide) or its selective delivery to fat tissue-adipocyte specific expression of NaKtide-ameliorate the systemic elevation of inflammatory cytokines seen in chronic obesity. Severe acute respiratory syndrome - coronavirus 2 (SARS-CoV-2), the RNA Coronavirus responsible for the COVID-19 global pandemic, invades cells via the angiotensin converting enzyme 2 (ACE-2) receptor (ACE2R) that is appended in inflamed fat tissue and exacerbates the formation of the cytokines storm. Both obesity and heart and renal failure are well known risks for adverse outcomes in patients infected with COVID-19. White adipocytes express ACE-2 receptors in high concentration, especially in obese patients. Once the virus invades the white adipocyte cell, it creates a COVID19-porphyrin complex which degrades and produces free porphyrin and iron and increases ROS. The increased formation of ROS and activation of the NKAL results in a further potentiated formation of ROS production, and ultimately, adipocyte generation of more inflammatory mediators, leading to systemic cytokines storm and heart failure. Moreover, chronic obesity also results in the reduction of antioxidant genes such as heme oxygenase-1 (HO-1), increasing adipocyte susceptibility to ROS and cytokines. It is the systemic inflammation and cytokine storm which is responsible for many of the adverse outcomes seen with COVID-19 infections in obese subjects, leading to heart failure and death. This review will also describe the potential antioxidant drugs and role of NaKtide and their demonstrated antioxidant effect used as a major strategy for improving obesity and epicardial fat mediated heart failure in the context of the COVID pandemic.

Angiotensin AT1 receptor antagonism by losartan stimulates adipocyte browning via induction of apelin

Adipocyte browning appears to be a potential therapeutic strategy to combat obesity and related metabolic disorders. Recent studies have shown that apelin, an adipokine, stimulates adipocyte browning and has negative cross-talk with angiotensin II receptor type 1 (AT₁ receptor) signaling. Here, we report that losartan, a selective AT₁ receptor antagonist, induces browning, as evidenced by an increase in browning marker expression, mitochondrial biogenesis, and oxygen consumption in murine adipocytes. In parallel, losartan up-regulated apelin expression, concomitant with increased phosphorylation of protein kinase B and AMP-activated protein kinase. However, the siRNA-mediated knockdown of apelin expression attenuated losartan-induced browning. Angiotensin II cotreatment also inhibited losartan-induced browning, suggesting that AT₁ receptor antagonism-induced activation of apelin signaling may be responsible for adipocyte browning induced by losartan. The in vivo browning effects of losartan were confirmed using both C57BL/6J and ob/ob mice. Furthermore, in vivo apelin knockdown by adeno-associated virus carrying-apelin shRNA significantly inhibited losartan-induced adipocyte browning. In summary, these data suggested that AT₁ receptor antagonism by losartan promotes the browning of white adipocytes via the induction of apelin expression. Therefore, apelin modulation may be an effective strategy for the treatment of obesity and its related metabolic disorders.

Mineralocorticoid Dysfunction during Critical Illness: A Review of the Evidence

The recent demonstration of the significant reduction in mortality in patients with septic shock treated with adjunctive glucocorticoids combined with fludrocortisone and the effectiveness of angiotensin II in treating vasodilatory shock have renewed interest in the role of the mineralocorticoid axis in critical illness. Glucocorticoids have variable interactions at the mineralocorticoid receptor. Similarly, mineralocorticoid receptor-aldosterone interactions differ from mineralocorticoid receptor-glucocorticoid interactions and predicate receptor-ligand interactions that differ with respect to cellular effects. Hyperreninemic hypoaldosteronism or selective hypoaldosteronism, an impaired adrenal response to increasing renin levels, occurs in a subgroup of hemodynamically unstable critically ill patients. The suggestion is that there is a defect at the level of the adrenal zona glomerulosa associated with a high mortality rate that may represent an adaptive response aimed at increasing cortisol levels. Furthermore, cross-talk exists between angiotensin II and aldosterone, which needs to be considered when employing therapeutic strategies.

Metabolic and cardiovascular outcomes of bariatric surgery

PURPOSE OF REVIEW

Bariatric surgery is an effective therapy for morbid obesity that also improves weight-related metabolic parameters and reduces morbidity and mortality. The purpose of this review is to consolidate our current understanding of metabolic, macrovascular and microvascular benefits of bariatric surgery and to provide an update.

RECENT FINDINGS

Early resolution of insulin resistance and type 2 diabetes mellitus (T2DM) varies by type of bariatric surgery and appears to be mediated by changes in secretion of gut hormones, metabolism of bile acids, expression of glucose transporters and the gut microbiome. Dyslipidaemia, atherosclerosis, microvascular complications of obesity and diabetes, systemic and tissue-level inflammation show evidence of regression and hypertension improves significantly after bariatric surgery.

SUMMARY

Bariatric surgery leads to improvements in obesity-related metabolic comorbidities such as dyslipidaemia, HDL functionality, hypertension, T2DM, insulin resistance and inflammation. It slows the atherosclerotic process and reduces cardiovascular and all-cause mortality. Recent data have demonstrated regression of the microvascular complications of obesity and diabetes including the regeneration of small nerve fibres. The magnitude of change in short-term metabolic effects depends on the surgical procedure whilst longer term effects are related to the amount of sustained excess weight loss.

Enalapril and treadmill running reduce adiposity, but only the latter causes adipose tissue browning in mice

This study investigated whether regulation of the renin-angiotensin system (RAS) by enalapril and/or aerobic exercise training (AET) causes browning of the subcutaneous white adipose tissue (sWAT). C57BL/6 mice were fed either a standard chow or a high-fat (HF) diet for 16 weeks. At Week 8, HF-fed animals were divided into sedentary (HF), enalapril (HF-E), AET (HF-T), and enalapril plus AET (HF-ET) groups. Subsequently, sWAT was extracted for morphometry, determination of RAS expression, and biomarkers of WAT browning. The HF group displayed adipocyte hypertrophy and induction of the classical RAS axis. Conversely, all interventions reduced adiposity and induced the counterregulatory RAS axis. However, only AET raised plasma irisin, increased peroxisome proliferator-activated receptor-γ coactivator-1α, and uncoupling protein-1 levels, and the expression of PR-domain containing 16 in sWAT. Therefore, we concluded that AET-induced sWAT browning was independent of the counterregulatory axis shifting of RAS in HF diet-induced obesity.